The airplane incurred substantial damage during a forced landing at about 1315 Eastern time following a partial loss of engine power. The flight instructor and private pilot received serious injuries. Visual conditions prevailed. During initial climb the tachometer indicated 1900 and the airplane would not gain altitude. The flight instructor elected to land in a field, but the airplane collided with trees before impacting the ground. The CFI was able to call for assistance, and both were taken to the hospital due to their injuries. Post-recovery examination of the airplane revealed the right magneto developed sparks to all corresponding plugs. The left magneto produced spark to one plug only.
